1. Field of the Invention
The present invention relates to methods of forming multi-layered patterned coating films.
2. Description of Related Art
Coatings are usually applied to automotive bodies, household electrical appliances, furniture, and like industrial products for protection and aesthetic purposes.
In recent years, innovative designs have been sought to enhance the appearance of such industrial products. Innovative designs herein mean, for example, nature-themed designs, artificial designs, traditional designs, and the like. Examples of nature-themed designs include a leather patterned appearance, stone patterned appearance, wood-grain patterned appearance, metallic appearance, marbled appearance, fur patterned appearance, fabric patterned appearance, “Washi” Japanese paper patterned appearance, etc. Examples of artificial designs include geometric patterns, etc. Examples of traditional designs include “Tsugaru Lacquering” patterned appearance, “mother-of-pearl work” patterned appearance, etc. “Tsugaru Lacquering” is a craft wherein distinctive patterns are created by applying layers of “urushi” Japanese lacquer and sanding them. “Mother-of-pearl work” is an “urushi” work which uses pearly inlays of processed shells such as abalone, mother-of-pearl, etc., and provides a high-quality appearance.
However, it is difficult to apply designs such as nature-themed designs and traditional designs to mass-produced industrial products because the application of these designs requires complicated steps. For this reason, easy methods of applying innovative designs to industrial products have been sought.
Unexamined Japanese Patent Publication No. 1998-43675 discloses an application method for forming a patterned layer comprising the steps of applying a metallic base coating composition to a substrate such as an automotive body or the like, and applying a pattern-forming coating composition to the surface of the base coating film to a film thickness thinner than its hiding film thickness. However, since the pattern-forming coating composition is applied by jet printing in this method, only a limited range of patterns can be formed.
Unexamined Japanese Patent Publication No. 2000-296360 discloses a method of forming a dot-patterned coating film comprising applying two or more kinds of coating compositions such as high-gloss solid color coating compositions, low-gloss solid color coating compositions, highly lustrous metallic coating compositions, etc. with a spray gun equipped with a plurality of coating nozzles. However, the patterns of coating films formed by this method are limited to dotted patterns, and since the method uses a single-layered coating film, only a limited range of designs can be formed.